In the manufacture of semiconductor devices, selective oxidation is used to target certain materials, such as silicon and oxides of silicon, while avoiding oxidation of other materials such as metals. Rapid thermal processing (RTP) is also used in the manufacture of semiconductor devices to change the characteristics of a deposited film or crystal lattice and generally includes processes such as annealing, silicidation, and oxidation of a substrate surface. The inventors have discovered that selective oxidation processes against metals in an RTP process using hydrogen and oxygen can undesirably result in the formation of moisture or condensation within the RTP chamber. The inventors have further observed that such moisture can act to transport contaminant particles onto the semiconductor wafer within the process chamber and further may result in undesirable oxidation of the metals on the substrate.
Accordingly, the inventors have provided improved methods and apparatus for selective oxidation against metals.